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Black Caiman (Melanosuchus niger)

Black Caimen
photo by wikiuser Rigelus

Common Name: Black Caiman
Scientific Name: Melanosuchus niger
Family: Alligatoridae – Alligator family
Locations: Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana, and Peru
Size: 7.25 – 14.1 feet (2.2 to 4.3 meters) , can grow to 16.5 feet (5 meters)

The Black Caiman is the largest living species of caiman, capable of reaching 16.5 feet long and reaching over a thousand pounds! They live in the Amazon River Basin, where they are one of the apex predators there. Once the Black Caiman reaches full size, only humans attempt to hunt them. The caiman feeds on a variety of animals such as snakes, fish, monkeys, frogs, and even other caiman. They hunt at night, where their excellent night vision help out.

At the end of the dry season, the females start to build their nests of soil and vegetation. Additionally, these nests are almost 5 feet (1.5 meters) long and 2 and a half feet (0.75 meters) wide. At the start of the wet season (May – June), the caiman lays between 30 – 60 eggs. The mother protects her nests from predators until they hatch. The eggs hatch between 42 – 90 days after being laid. The mother helps dig the hatchlings out of the nest. Then, the offspring stick close to their mom. Even with their mom’s protection, a large number of the offspring die.

Black Caiman Conservation

The International Union for the Conservation of Nature (IUCN) Red List categorizes the Black Caiman as Conservation Dependent. The IUCN Red List no longer uses this category. The caiman’s status hasn’t been reassessed since 2000 when they were placed there. Before, they were categorized as endangered due to over hunting of the species. Hunting of the species has slowed down thanks to legal protections.

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American Crocodile (Crocodylus acutus)

American Crocodile
photo by wikiuser Mattstone911

Common Name: American Crocodile
Scientific Name: Crocodylus acutus
Family: Crocodylidae – Crocodile Family
Locations: Belize, Colombia, Costa Rica, Cuba, Dominican Republic, Ecuador, El Salvador, Guatemala, Haiti, Honduras, Jamaica, Mexico, Nicaragua, Panama, Peru, United States, Venezuela, and Bolivia
US Location: Florida
Average Male Size: 9.5 – 13.1 feet (2.9 – 4 meters)
Average Female Size: 8.2 – 9.8 feet (2.5 -3 meters)
Maximum Size: 20 feet (6.1 meters)

The American Crocodile has the most widespread range of any crocodile in the Americas. They reach from southern Florida, through Central America, and down to northern South America. They live in fresh or brackish water of estuaries, lagoons, and mangrove swamps.

The American Crocodile breeds during the dry season. The males are highly territorial and fight other males for the best land. The courtship and breeding takes place in the water. The male’s main advertisement to females is 1 to 3 headslaps. If this is acceptable for the female, then she either puts her head on his back / head or performs some snout lifts. Next, the male lets out a low frequency noise that makes water blow up off of his back, called water dancing. Finally, the two mate in the shallows.

The female builds their nests on elevated, well drained soil. The female lays between 30 – 60 eggs. Temperature determines the sex of the offspring. Temperatures between 88- 91° F (31.1 – 32.7° C) produce mostly male offspring. Meanwhile, temperatures lower than 88° F (31.1° C) result in mostly females. The female parent protect the nest from scavengers such as raccoons and iguanas. The eggs hatch in 75 – 80 days at the start of the wet season. The female helps dig ups the hatched babies and carries them to the water.

American Crocodile Conservation

The International Union for the Conservation of Nature (IUCN) Red List classifies the American Crocodile as Vulnerable to Extinction. The Croc’s populations has improved than it previously had been. It was listed as Endangered before conservation work was done to help save them. Unfortunately, they were over-hunted for their hides before being listed on the US Endangered Species List in the 1970s. However, they moved from listed as federally endangered to federally threatened. Protections are still in place to help conserve the species from overharvesting. Unfortunately, their habitat is under threat of destruction to make room for more urban areas.

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Gharial (Gavialis gangeticus)

Gharial
Male Gharial – photo by Charles J Sharp

Common Name: Gharial, Gavial, and Fish-eating Crocodile
Scientific Name: Gavialis gangeticus
Family: Gavialidae – Gharial family
Locations: Bangladesh, India, and Nepal
Female Size: 8.5 feet (2.6 meters) – 14.75 feet (4.5 meters)
Male Size: 10 feet (3 meters) – 20 feet (6 meters)

The Gharial is known for their long, narrow snout that is adept at catching fish. Males of the species develop a gross looking growths called a ghara on the tip of their snouts once they reach sexual maturity. Ghara means Mud Pot in Hindi. They use the ghara to vocalize more loudly and blow bubbles during their mating displays.

The mating season for the frogs happens during the dry season, between March and April. The males stake out their territory and defend it from rival males. Females in the territory mate with the male and she then lays an average on 40 eggs. Their eggs are the largest eggs of all the living crocodilians, averaging over 5 ounces. The male provides no parental care for their offspring and will move onto reproducing with other females. The female stays to protect her nest from predators. The eggs hatch between 30 – 80 days. After hatching, the mom still protects the babies for weeks and even months.

Gharial Conservation

The International Union for the Conservation of Nature (IUCN) Red List classifies the Gharial as Critically Endangered. Their habitat has been drastically altered due to damming and diverting water from the rivers. Gharials don’t do well far away from the river. These alterations to the habitat causes them to have to travel farther on land when moving to new spots in their river, increasing their chance of dying. Overfishing is also rampant in rivers that the Gharial is found in. This reduces their food source and they get stuck or injured by nets.

Uncategorized

CROCtober

Welcome to CROCtober, the annual celebrations of all things crocodilian, the animal group – not the shoes, during October. The term Crocodilians includes crocodiles, alligators, caimans, and gharials. These creatures are often misunderstood as furious, killing machines but there’s more to them than that. Crocodilians are one of the most endangered group of animals on the planet. Out of the 23 species, 7 of the species are listed as critically endangered. Additionally, 4 species are listed as vulnerable to extinction. That’s not great.

Over the month of CROCtober, I plan to highlight the different species of crocodilians, the troubles they face, some researchers who study them, and how you can help save the crocs. Don’t worry, frog content will still be posted. Stay tuned!

Frog of the Week

Cape Platanna (Xenopus gilli)

Cape Platanna
photo by flickr user Chris Verwey
Conservation status is Endangered

Common Name: Cape Platanna, Gill’s Plantanna, and Cape Clawed Toad
Scientific Name: Xenopus gilli
Family: Pipidae – Tongueless Frog family
Locations: South Africa
Size: 2.3 inches (60 mm)

The Cape Platanna is an aquatic frog that inhabits the highly acidic seepages, marshes, ponds, and lakes of coastal South Africa. These waterbodies are dark in color, allowing the frogs to blend in. The Platanna are able to “see” in this water due to their highly developed lateral line system. This system always them to detect small vibrations in the water. The frogs have highly webbed clawed toes on their back legs to help them swim. They only come to the surface when their wetlands dry up during the summer or when they want to migrate ponds during the mating season. The frogs aestivate during the summer when their ponds dry up by digging deep into the mud.

The Cape Platanna breeds during the winter months between July to October. Unlike most frogs, members of the family Pipidae lack vocal sacs. To communicate with female frogs, the male frogs make a series clicks. Once the female selects her mate, the male grasps her around the waist in the amplexus position. Then, the female lays between 300 – 400 eggs while the male fertilizes them. Neither parent is known to provide any parental care. Once the eggs hatch, the tadpoles take 120 days to complete their metamorphosis.

Cape Platanna Conservation

The International Union for the Conservation of Nature (IUCN) Red List categorizes the Cape Platanna as Endangered with Extinction. There is believed to be only 5 locations where the frogs live. Most of the wetlands that the frog calls home as been filled to make room for housing development and farm lands. Additionally, the frog hybridizes with the African Clawed Frog (Xenopus laevis), reducing their numbers. Better protections are needed to help save them.

Frog of the Week

Holy Cross Frog (Notaden bennettii)

Holy Cross Frog
photo by wikiuser Tnarg 12345

Common Name: Holy Cross Frog, Crucifix Frog, and Crucifix Toad
Scientific Name: Notaden bennettii
Family: Myobatrachidae – Australian Ground Frog family
Locations: Australia
Size: 2.7 inches (6.8 cm)

The Holy Cross Frog is a fossorial species of frog found in the  black soil plains and semi-arid grassland regions of western New South Wales and Queensland. During the dry times, the frog burrows down in the ground and surrounds itself in a cocoon to preserve water. They are capable of digging down almost 10 feet (3 meters)! Due to their fossorial lifestyle, the frogs feed primarily on ants and termites. When threatened by predators, the frogs produce a sticky, glue-like substance that predators don’t want to eat. It is advised to wash your hands after handling the Holy Cross Frog and basically any frog.

Once the heavy rains come, the frog will emerge from the ground, ready to breed. The male frogs will move to temporary ponds created by the rains and start to call out to females. The call sounds like a woo. Once the female arrives at the pond, the male glues himself to her back due to his smaller size. Next, the female lays her eggs and the male will fertilize them. Neither parents provide any parental care for their offspring.

Holy Cross Frog
photo by flickr user eyeweed

The International Union for the Conservation of Nature (IUCN) Red List categorizes the Holy Cross Frog as Least Concern for Extinction. The only threats to the species are habitat loss due to farming, climate change, and the introduction of the invasive Cane Toad (Rhinella marina). Researchers have been trying to get the frogs to breed in captivity just in case but have been struggling. Surprisingly, the answer to this problem was a Youtube Clip of a thunderstorm. This clip helps simulate heavy rain storms that gets the frogs in the mood.

New Species

2 New Species of Waterdogs

The Waterdogs are fully aquatic species of salamanders that are paedomorphic. This means that they retain their larval characteristics (gills, etc) throughout their life. They are often mysterious, often living at the bottom of drainages, ponds, and lakes.

Researchers, Craig Guyer, Christopher M. Murray, Henry Bart, Brian I. Crother, Ryan E. Chabarria, Mark A. Bailey, and Khorizon Dunn, have described two new Waterdog species from the southeastern United States. You can read the article here. The two waterdogs were considered to be Gulf Coast Waterdog (Necturus beyeri) but they are physically different than it. Also the researchers suggest changing the name of the Gulf Coast Waterdog to the Western Waterdog.

Escambia Waterdog – photo by Craig Guyer

The first of the new species is the Escambia Waterdog (Necturus mounti). The larvae lacks white spots which differs from the Gulf Coast Waterdog. The adults lack spots on their mandible chin and on the sides of their belly. Their belly is a bright white color as well.

Apalachicola Waterdog – photo by Craig Guyer

The second of the species is the Apalachicola Waterdog (Necturus moleri). They as well lack white spots on their larvae that differs it from the Gulf Coast Waterdog. The adults have spots on their mandible chin and on the sides of their belly. Their belly is dull white in color. Both of the new species can be found around the Florida – Alabama border.

Frog of the Week

Paradoxical Frog (Pseudis paradoxa)

Paradoxical Frog
photo by Hans Hillewaert
least concern

Common Name: Paradoxical Frog, Paradox Frog, Shrinking Frog
Scientific Name: Pseudis paradoxa
Family: Hylidae – Tree Frog Family
Locations:  Argentina, Bolivia, Brazil, Colombia, French Guiana, Guyana, Paraguay, Peru, Suriname, Trinidad and Tobago, and Venezuela
Size: 1.7 – 3 inches (45 – 75 mm)

The Paradoxical Frog is named after a strange phenomenon during their metamorphosis. Their tadpole is the largest tadpole in the world, almost reaching 10 inches (25 cm) long! That is over three times larger than the length of an adult frog! What a paradox! Yet, not all tadpoles exhibit the paradox. Tadpoles that are born in temporary bodies of water with predators transform quickly and leave the water before they get to massive sizes. In permanent bodies of water, they transform slower, thus allowing more growth time.

The Paradoxical Frog is a member of the Tree Frog family – Hylidae but they are never seen in the trees. They live in and around permanent and temporary ponds. These are the same bodies of water that they breed in. The males will call for the ponds for the females. Once the female arrives, the male will grasp her from behind in the amplexus position. Then, the female will start laying her eggs and the male will fertilize them. The eggs are laid in the vegetation near the shore. Neither parent provides any parental care.

The International Union for the Conservation of Nature (IUCN) Red List categorizes the Paradoxical Frog as Least Concern for Extinction. They have a wide spread range and are common throughout it. Some populations are facing declines due to habit loss due to urban development and agriculture.

Frog of the Week

Magdalena Giant Glass Frog (Ikakogi tayrona)

Common Name: Magdalena Giant Glass Frog
Scientific Name: Ikakogi tayrona
Family: Centrolenidae – Glass Frog family
Locations: Colombia
Size: 1.2 inches (28 mm)

The Magdalena Giant Glass Frog is found in the Sierra Nevada de Santa Marta mountain range in the Magdalena department of Colombia, at altitudes up to a mile (1790 meters) high. They are an arboreal species of frog, living up in the trees. During the day, the frogs will hide on the back of leaves, camouflaging in with their translucent skin. Glass Frogs are really small, so even a frog reaching not even 1.5 inches long is considered gigantic.

The males of the species will mark out territory in leaves over hanging a stream. They will fight other males that enter their territory. The males even have humeral spines on their arms that they use to fight the other males. Eventually, the males will start calling for the females. Once the females arrive, the male will grasp her from behind in the amplexus position. Then, the female will lay her eggs on the leaves and the male will fertilize them.

The Magdalena Giant Glass Frog is the only known Glass Frog known that females will provide parental care for their offspring. In the other species, parental care is either provided by the male or not at all. The females will brood the eggs, protecting the eggs from predators and keeping them hydrated. Eventually, the eggs will hatch and the tadpoles will fall into the stream.

The International Union for the Conservation of Nature (IUCN) Red List categorizes the Magdalena Giant Glass Frog as Vulnerable to Extinction. They are found only in a small area where habitat destruction is an increasing problem.

Frog of the Week

Western Chorus Frog (Pseudacris triseriata)

photo by Todd Pierson

Common Name: Western Chorus Frog or Midland Chorus Frog
Scientific Name: Pseudacris triseriata
Family: Hylidae – Tree Frog family
Locations: Canada and the United States
US Locations: Iowa, Illinois, Indiana, Kentucky, Michigan, New York, Ohio, and Tennessee
Size: .3 – 1.5 inches (10 – 37 mm)

The Western Chorus Frog is a poorly named frog, due to it not living anywhere close to the west. It used to be part of a species complex with other Chorus Frogs, such as the Upland Chorus Frog (Pseudacris feriarum), but they were eventually all split into their own species. The Western Chorus Frog is often confused with other species of chorus frogs. Differences between the chorus frog species have to do with location and leg size so it can be really confusing. While chorus frogs are a member of the tree frog family – Hylidae, they are not found climbing high in the trees but usually around ground level. Due to their small size, they can be rather hard to find. Best time to locate them is during the breeding season when they are calling.

 Ohio Department of Natural Resources Division of Wildlife

The Western Chorus Frog starts to breed in February or March, depending on when the snow melts. They will continue to breed until the end of April or early May. The males of the species will start to call from temporary bodies of water like flooded ditches, flooded fields, and ponds. Females will come to the water and choose a mate. Once that happens, the male will grasp the female from behind in the amplexus position. Then the female will lay her eggs and the male will fertilize them. The female can lay 300 eggs at a time. Neither parent provides any parental care for the offspring. The eggs hatch a week later and a tadpole emerges. The tadpole takes 3 months to complete their transformation into a juvenile frog.